Which of the following is a requirement for using the prescriptive option for landscapes?

The requirement for using the prescriptive option in landscapes is that automatic controllers utilizing evapotranspiration (ET) or soil moisture data must be installed. This approach promotes more efficient water use by ensuring that irrigation adapts to the actual moisture needs of the plants, taking into account environmental conditions that affect evaporation and transpiration rates. The use of such advanced irrigation controllers allows for precise application of water, reducing waste and promoting plant health, which aligns with sustainable landscape practices.

The other options do not meet the criteria established for the prescriptive approach. Manual irrigation systems do not provide the same level of efficiency and adaptability as automated systems. Requiring sprinkler systems to operate without sensors contradicts the intent of optimizing water use, as sensors are crucial for monitoring moisture levels and preventing over- or under-watering. Similarly, mandating flood irrigation for all areas would not be practical or appropriate for many landscape scenarios, as this method is not suitable for all types of plants or soil conditions, thereby undermining the goal of water conservation and efficient landscape management.